Chavez's breathing problems worsen with infection

Venezuela president Hugo Chavez's breathing problems have worsened and he is suffering from a new, severe respiratory infection after undergoing cancer surgery in Cuba, his government said.

Reading the latest official assessment of Mr Chavez's health, information minister Ernesto Villegas said the 58-year-old socialist leader's condition was very delicate.

"Today there is a worsening of his respiratory function. Related to his depressed immune system, there is now a new, severe infection," Mr Villegas said.

"The president has been receiving high-impact chemotherapy, along with other complementary treatments... his general condition continues to be very delicate."

Mr Chavez made a surprise pre-dawn return to Venezuela from Cuba two weeks ago.

The government said he is in a tightly guarded suite at a Caracas military hospital.

He has not been seen in public nor heard from since his December 11 operation in Havana, his fourth cancer surgery since the disease was detected in his pelvic region in mid-2011.

The government has given mixed messages about his condition, saying last week that he was still suffering from respiratory problems before declaring the next day that he had presided over a meeting with aides.

Then vice president Nicolas Maduro, his chosen successor, disclosed the chemotherapy treatment late Friday, before saying the next day that Mr Chavez was still sending instructions about political and economic policies.

Hundreds of people joined an opposition-led march on Sunday demanding the government reveal more details about the condition of the president of a nation that sits atop the world's largest proven oil reserves.